Blower



April 22, 1947. R, A, A E 2,419,411

BLOWER Filed Nov. 13, 1944 {Sheets-Sheet 2 Patented Apr. 22, 1947 UNIT ED STAT E S 'PATEN T OFF 1 C E (BLOWER Btibei't-A. Mayne, bayton, Application November 13,1944, SerialNd.-"563,234 6 Claims. (01.29.0434) This iinvention're'lates to'a blower and more particularly to a blower ofthe centrifugal'type.

An object of this invention is to provide a blower having the fan blades arranged to interlock an annular ring in such a'i'nanner'that the fan may be easily assembled by unskilled labor and at the same time produce'a rigid, dependable and efficient fan assembly at a low cost of production.

Another object of this invention is to provide fan blades having tabs clamped between apair of rings or hoops in such a manner that the blades are held in a rigid relationship with respect to eachother and at the same time the parts are easily assembled.

Another object of this inventionis to provide aerodynamic fan blades for use in a fan of the centrifugal type.

Another object of this invention is to provide extensions projecting from the ends of the blades, the width of each extension being equal to the spacing of the blades, so that the blades are held in spaced relation by the extensions being positioned edge to edge on the retainingmeans'.

Other objects and advantages reside in the construction of parts, .the combination thereof and the mode of operation, as will become more apparent from the'following description.

In the drawings:

Figure 1 is a perspective'view of a centrifugal type blower.

Figure 2 is an enlargedfragmentary detail view taken substantially on-the line 2-2 of Figure 1.

Figure 3 is a fragmentary view s'howinga step in the assembly.

Figure 4 discloses a fan blade before assembly. Figure 5 is a cross sectional viewtaken sub stantially on the line 55 ofFigure 4.

Figure 6 is a cross sectional view of a modified fan blade.

Figure '7 is a fragmentary enlarged perspective view showing the hook arrangement of the tab as it appears on the stamping of the blade before assembly.

Figure '8 showsa spider-like support for the fan assembly.

Figure 9 is a cross sectional 'view taken substantially on the section line'99 of Figure 8.

vIn the manufacture of. :fan blades various methods of supporting the bladeshave been used. For example, insome fan assemblies, the blades are integral with the marginal rims,as*shown in my copending application for United States Letters Patent Serial No. 52 5;810 filed March 8, 1944, for Centrifugal-fan; -In;.other-fan assem- '2 blies the blades have been riveted the rims, welded to the rims or'seated in sockets ornotches formed in the rims. e

In the device .disclosed herein, each 'ofthe blades is provided with extensions that are held in "position by clamping. rings, the width of the extensions being such that the extensions are used in'spa'cing the blades from each other by abutting each other edge to edge.

Referring to the drawings, the reference character l0 indicates a 'fan blade having a curved body portion 1 2. Insord'er to produce anaerodynamic fan blade, the marginalportion M has "been formed into a substantially tear-shaped co'ntour.

Each blade is provided with an extension portionl' 6 that isinitially formed into a hook-shape 'by bending the end l8,as clearly shown in-Fi'gure '7. ihe widtl'i of-the extension or tab portion 16 is equal-to the spacing-between theblac'le's. The blades are assembled upon a pair of bars 20, each-having a rectangular cross sectionalarea, as clearly shown in Figure 2. The hook extensions 15 are merely hooked over the edges of the bars '20, the extensions 16 adjoining each other along the dges. The bars 20 have a length equal to the circumference of the blower, as measured on the inside of the tabs. After all of the blades used in the blower have been assembled on the b'arS' -ZO, the-bars 26, together -with theblades, may be passed through suitable rollers whichbend the ends l8' into contact with the inner margins of the bars 20 and at the same time curve the bars 2i], so as to formthe assembly into a'circular or cylindrical contour. The ends of the bars 26 may be buttwelded, so asto form hoops or rings for supporting the fan blades.

A clamping or shroud ring 22, thathasa cross sectional area simulating an angle bar, is forced upon the oiiter periphery of the extensions I6, so as'to rigidly clamp the extensions between the flanged'portio'n 2 4 o'f'the ring 22 and the ring .20. The ring 20 has an inwardly directed flange portion ZB Which functions as-a reenforcing ring to maintain the blower assembly in true circua lar form. The ring 22 may be formed in any 011901 a plurality of methods. It may be formed by spinning the -metal, it may be formed by stamping, which is the preferred mo'deof forming the ring, or it may be formed from 'an angle barthat has been curved into circular formation; The ring 22 may be spot-welded or riveted at spaced intervals to some ofth extensions lifi and'thering 20'.

Jfit the contour of the blades.

Each end of the blower may be supported upon a pair of hubs 32 by diametrically disposed spokes 30. Instead of two spokes for each hub, three, four or any suitable number may be used. In the preferred embodiment disclosed herein, each spoke consists of a pair of round bars 34, having the ends spot-welded to the inwardly directed flange 2t and the center portion 36 formed into a semi-circular shape, so as to embrace the hub 32. The spokes may be welded together at 38, so as to rigidly hold the spokes around the hub. Instead of utilizing a pair of bars forming the diametrically disposed spokes, the spokes could be formed in any other suitable manner,

as for example by stamping the sheet metal.

spokes out ,of

"each of the sheet metal blower blades terminating in a pair of extensions, the extensions of each blade lying in a common plane substantially normal to a portion of the arcuate blower blade, the

Referring to the modification disclosed inFigures 8 and 9, a spider has been shown for supporting the fan assembly. This spider includes a hub as provided with an axially disposed apertur'e 42 and a plurality of radially disposed pairs of apertures M.

This hub is mounted upon a suitable drive shaft 46, as is 'well known to those skilled in the art. The fan assembly is supported in spaced relation from the hub by a plurality of U-shaped members 56, having the ends of the legs seated in the apertures 44 and fixedly secured thereto either by press-fitting or by welding.

The bight or transverse bar 52 of each U- .shaped member 53 is positioned in contact with selected blades I9 and welded thereto. A portion of the legs is curved at E l so as to snugly By utilizing two spaced bars forming the legs of the U-shaped member joined by the transverse bar, a supporting spider is provided that has greater rigidity than if the spoke-like members were to end when coming into contact with the'blades. Furthermore, the transverse bar and the curved portion of the U-shaped member are positioned on the convex side of the blades and, so to speak, push the blades when driving the fan. This mounting assembly is easily produced, is efiicient, has the required strength and at the same time low impedance to the flow of air.

In assembling the parts the squirrel-cage-like fan may be first assembled, then the hub 46 and the U-shaped members 50 assembled. The squirrel-cage-like fan assembly and the hub may then be placed in a cradle or a jig, holding the hub in concentric relation with respect to the fan blades, the cradle or jig holding the fan in a true circular relation, the bight of the U- shaped supports being welded to selected blades while the assembly is held in the jig, so as to produce a fan assembly wherein the fan and the hub are concentrically disposed with respect to each other.

For some purposes the shroud ring 22 may be omitted. In order to improve the appearance of the fan assembly and to secure the blades in position, the extensions together with the rings, or in other words, the ends of the fan assembly, may be galvanized. In the event the shroud ring is eliminated and it is desired to produce a high speed fan, the extensions may be located on the inside of the rings 20, so that the centrifugal force exerted upon the blades is transmitted'through the extensions outwardly to the rings 20. In such an event, the tabs would be folded outwardly over the rings 20, then galvanized, so as to partly conceal the tabs and so as to bond the extensions to the rings 26.

Although the preferred embodimentof the dewidth of the extensions being equal to the spacing of the blades so that the edges of the extensions of adjacent blades contact each other, the ends of the extensions being folded inwardly and under the rings so as to hold the blades in position with respect to the rings.v

2. In a blower assembly a pair of spaced rings, sheet metal blower blades mounted between the rings, each of the sheet metal blower blades terminating in a pair of extensions, the extensions of each blade lying in a common plane substantially normal to a portion of the arcuate blower blade, the width. of the extensions being equal to the spacing of the blades so that the extensions of adjacent blades contact each other and overlie the rings, the ends of the extensions being folded inwardly and under the rings so as to hold the blades in position with respect to the rings, and a pair of juxtaposed rings overlying the extensions so as to clamp the extensions between the first rings and the second rings, said second rings counteracting the centrifugal force exerted by the blades when the blower is in motion.

3. In a blower assembly a pair of spaced rings, sheet metal blower blades mounted between the rings, each of the sheet metal blower blades terminating in a pair of extensions, the extensions of each blade lying in a common plane substantially normal to a portion of the arcuate blower blade, the width of the extensions being equal to the spacing of the blades so that the extensions of adjacent blades contact each other and overlie the rings, the ends of the extensions being folded inwardly and under the rings so as to hold the blades in position with respect to the rings, and a pair of juxtaposed rings overlying the extensions so as to clamp the extensions between the first rings and the second rings, said second rings counteracting the centrifugal force exerted by the blades when the blower is in motion, said second rings having inwardly directed flange portions for reenforcing the margins of the blower to hold the ends of the blower circular.

4. In a blower assembly the combination including a pair of spaced rings and sheet metal arcuate blower blades mounted between the rings, each of the sheet metal blower blades terminating in a pair of extensions, the extensions of each blade lying in a common plane substantially normal to a portion of the arcuate blower blade, the width of the extensions being equal to the spacing of the blades so that the edges of the extensions of adjacent blades contact each other, said extensions being placed edge to edge in contact with said rings, and a second pair of rings cooperating with the first pair of rings to clamp the extensions in position.

5. In a blower assembly the combination in cluding a pair of spaced rings and sheet metal ar cuate blower blades mounted between the rings, each of the sheet metal blower blades terminating in a pair of extensions, the extensions of each blade lying in a common plane substantially normal to a portion of the arcuate blower blade, the width of the extensions being equal to the spacing of the bladesso that the edges of the extensions of adjacent blades contact each other, said extensions being placed edge to edge in contact with said rings, and a second pair of rings cooperating with the first pair of rings to clamp the extensions in position, the ends of said extensions overlapping at least one of said rings to hold the rings axially.

6. In a blower assembly the combination including a pair of spaced rings and sheet metal arcuate blower blades mounted between the rings, each of the sheet metal blower blades terminating in a pair of extensions, the extensions of each blade lying in a common plane substantially normal to a portion of the arcuate blower blade, the

width of the extensions being equal to the spacing of the blades so that the edges of the extensions of adjacent blades contact each other, the extensions contacting the rings, the ends of the extensions being folded over the edge of the rings to hold the blades and the rings in fixed axial relation with respect to each other.

ROBERT A. MAYNE.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

